Things that evolve – (2) Natural Selection

There’s a new review of James Shapiro’s bookhere. The author, Adam Wilkins, is critical of Shapiro’s main thesis, but accepts there’s a growing body of opinion in certain evolutionary disciplines against classic Neodarwinism.

One of his observations is that Shapiro, like others, downplays the role of natural selection to a bit-part player. He quotes and comments thus:

The matter of selection is then virtually ignored until the final section of the book. There we read, as one of nine bullet-points that summarize the core message: The role of selection is to eliminate evolutionary novelties that prove to be non-functional and interfere with adaptive needs. Selection operates as a purifying but not creative force [emphasis added].

I cannot imagine many evolutionary biologists subscribing to that position.

Of course, evolutionary biologists are not the only players here, as he admits elsewhere in the review. But in support of his opposition, one strand of Wilkins argument is the palaeontological:

The arguments from paleontological evidence for the importance of natural selection largely concern the observed long-term trends of morphological change, which are visible in many lineages. It is hard to imagine what else but natural selection could be responsible for such trends, unless one invokes supernatural or mystical forces such as the long-popular but ultimately discredited force of orthogenesis.

This is what attracts my attention here. In the Origin of Species, as I stated in my previous post, Darwin held a deeply perfectionist position on evolution. There is no doubt that he saw evolution as acting towards not merely the change, but the perfection, of species. This follows from his initial analogy with artificial selection, which he makes clear includes not just the selection of desirable features like speed or long ears, but the overall “improvement of the breed” (a phrase much loved in Victorian livestock breeding as well as the Eugenic Movement). The breeder unconsciously selects “the best” even when not considering specific traits, and so there is a trend to increasing “perfection”.

This implies some absolute, if virtual, “goal” for change (perfection) within nature, and also the unstated assumption that, overall, the environment in loco mentis applies a consistent selective pressure towards that same unintentional goal. Such a consistency would seem a necessary condition for Wilkins’ “observed long term trends of morphological change” in the natural world. But just as Darwin’s concept of perfection is now seen as meaningless (when it is no longer competing with special creation or exemplified by artificial selection), so the environment is increasingly obviously found to be an endlessly swirling and eddying combination of a multitude of factors, without any overall direction. Just as even the simplest organisms are found to be well and complexly adapted to their niches.

This is easy to see in iconic examples like Darwin’s finches, or the peppered moth, whose morphological changes come and go with cycles in weather or other reversible factors. Climate warms and cools even century by century, coastlines flood and recede, species arrive and change the ecology radically, or succumb and reverse those changes. Given such a kaleidoscopic shift in ecologies, and therefore in what constitutes “fitness”, the steady progression of morphological trends appears to occur despite natural selection, rather than because of it. Yet Wilkins’ argument is that it is hard to imagine any other cause than natural selection without invoking the supernatural.

Notice, though, how the argumentation process has developed (evolved?) since Darwin. The Origin of Species opposed its argument principally to special creation. The aim, as I’ve argued before, may have been mainly to propose a plausible alternative that could capture the imagination, but the method was to show how natural selection explained the evidence better. One good example of this is Darwin’s take on island fauna: you’d expect a Creator, he said, to place similar island-friendly species wherever such habitats occur. Instead, as on the Galapagos, the flora and fauna resemble an impoverished and adapted version of the nearest mainland species.

150 years on, the adequacy of selection is being questioned by people like Shapiro. The response is not to return to Darwin and say, “Look, the evidence is here,” because the evidence isn’t actually good enough. Instead, the reply is, “What else but selection could explain this, without allowing God a foothold?” So Darwin displaced the then-prevalent theory, creationism (in an older sense than today’s), by an appeal to better evidence; his successors, finding the evidence insufficient, merely dismiss the original theory out of hand.

Natural selection, then, has in Wilkins’ presentation “evolved” so that it still produces directional change, but with no longer any concept of “perfection” to provide that direction. And he’s done so on the mistaken assumption that creationism went extinct at the hands of natural selection, its main predator. Iconoclasts like Shapiro would seem to represent some unexpected immigrant super-predator, like stoats in New Zealand.

And so evolution explains everything…

About Jon Garvey

Training in medicine (which was my career), social psychology and theology. Interests in most things, but especially the science-faith interface. The rest of my time, though, is spent writing, playing and recording music.

7 Responses to Things that evolve – (2) Natural Selection

Wrt the ‘adequacy of selection,’ it would seem a significant aspect of the discourse depends on what one means by anaology. ‘Selection’ is an ‘agent-like’ force or energy, taken-on by the biological sciences and other sciences of nature. But can ‘selection’ stand as a legitimate basis on which to conclude that ‘evolution explains everything,’ or is that just an example of the ideology of ‘universal evolutionism’?

Don’t suggestions like, “if something is ‘natural,’ then it is/was ‘selected’ at some point,” make hay on their analogy between agency and essence?

‘Selection’ in the ‘natural’ sense is deemed a ‘law’ of change. But of course, as Jon hints in Part I, it is questionable whether such a ‘law’ could be transferred to explain intentional, goal-oriented, purposeful change at higher-order discussions of human society, culture, religion, language, politics, etc. I’ll be interested to see if Shapiro extends his challenges to Darwinian ideas into ‘extra-natural’ realms which biologists have sometimes found it enticing to venture.

Regardless of whether Wilkins thinks ‘natural selection’ has ‘evolved’ (with the implication of progress or for the better), he still cannot escape the personality and agency of the scientists themselves who were responsible for intentionally changing the language, using new theories, approaches, ideas, etc. To suggest that experiment everywhere and always drives science is to over-speak. Those who make theories, based on experiments, data or simply an insightful discovery made while thinking somewhere outside of the ‘laboratory’ are the ones involved in neo-logy (from neologism).

‘Natural selection’ was a neologism in its day. It will be interesting to see if/when another ‘analogy’ to agency is introduced in biology, wrt natural change and emergence, that may challenge Darwin & Wallace’s covering theory. It would take (an) iconoclast(s) on a scale and pattern different than Behe and Dembski to achieve this.

“Ill be interested to see if Shapiro extends his challenges to Darwinian ideas into extra-natural realms which biologists have sometimes found it enticing to venture.”

I doubt he would personally, Gregory, given that he’s just a humble bacterial kind of a guy. But inherent in his system would seem to be some of those systems biology ideas of emergence (since he appears unhappy with personal agency), and emergence seems to be very much a concept in use in the study of mind, and maybe of sociological areas too (though you’d know if that’s true that far better than I).

There’s something positive to be said about knowing the limitations of one’s ‘home’ field when one is a ‘scientist.’ Probably Shapiro’s focus predominantly on biology-only deserves some respect, like the ‘humble bacterial guy’. Unfortuantely, the shadow of socio-biology still darkens discussions based on trust between sociologists and biologists.

The ‘systems’ people, following in the tradition of Alexandre Bogdanov, Norbert Weiner and Ludwig von Bertalanffy, are sometimes quite different in their orientation and aspirations.

A question to ask is what are the differences and similarities between ‘evolution’ and ’emergence’ and at what levels of discussion are these terms properly applied? Is ’emergence’ (scientific, philosophical and perhaps theological) a spectre of the new ‘evolutionary’ revolution now upon us?

Well, as I understand “emergence” from something like Denis Noble’s Music of Life it’s the faith that at a certain level of complexity more-than-the-sum-of-the-parts kicks in in a big way. So some “ordinary” evolutionary process begins to produce self-organising cells that really do plan their own destiny. Nervous systems get so many feedback loops that they become minds. All very plausible – but then so is natural selection if you don’t have to pin it down to reality.

I suppose by the same token multiple organisms become balanced ecosystems (Gaia emerges), individuals become societies, and the Internet becomes the world brain.

Well, attaching the pronoun ‘their’ to ‘cells’ is of course somewhat problematic for the linguist. Does a ‘cell’ have a ‘self-identity’? Same thing with ‘nervous systems’ becoming ‘minds.’

Again, we return to the topic of agency and the question of where it belongs, which fields address it, and which fields merely mechanize or automatize it.

The notion of ’emergence’ reaching ‘thresholds’ that ‘evolution’ theories do not directly address is important. But the jury is still out on how and if ’emergence’ will or even could improve upon the ‘evolutionary’ paradigm.

Does ’emergence’ suggest an ‘agent-like’ substitute for ‘natural’ or ‘artificial’ selection? Or is that dichotomy itself an outdated one?

Of course, the other side of Part I & II in this series is to speak of “Things that don’t evolve.” But most people do not appear to be ready for that yet…

Well, clearly an animal is an “agent” in a way that a stone isn’t, and yet not in a way that a person is an agent. Chemistry, emergence, vital force … I guess there’s a physical explanation at some level.

Shapiro’s (and similar people’s) position is that part of that agency involves evolutionary mechanisms – they do evolution rather than it’s being done to them. That may turn out to be more important than natural selection, though will never replace it completely as NS is only “some reproduce better than others” when it comes to it.

I deliberately left the things that don’t evolve for you, having scraped what remains from the bottom of the barrel for my own two posts ;-).